1. Field of the Invention
This invention is generally directed to systems for transporting, supporting and storing cargo containers of the type utilized in local and long distance shipping and warehousing of bulk goods or freight and more particularly to such a system which incorporates support frames which are interlockable with the shipping containers and which serve to support the shipping containers when unloaded from a transporting vehicle such as a flat bed truck, trailer, water vessel or railway car. In one embodiment of the present invention, the frames are designed to be self-elevating with respect to the transporting vehicle so that the frames may be raised and lowered in order to permit a plurality of legs to be extended horizontally and then vertically to support the containers above the bed of the transporting vehicle. After elevation, the vehicles may be simply driven from under the frames and containers. Thus, the containers are loaded or unloaded without elevating equipment such as hoists, cranes or forklifts.
In the preferred embodiments, the frames are interlocked with alignment cradles which are mounted to the transport vehicles. The cradles may include guidance elements which cooperate with lift assemblies which elevate the cradles, support frames and shipping containers relative to the transporting vehicle. In another embodiment, auxiliary raks are selectively mounted to the ends of the support frames.
2. History of the Related Art
Due to the high costs associated with shipping goods both locally and long distance, and due to the need to standardize the manner in which freight is warehoused and shipped, many goods are transported in large shipping containers. The shipping containers are conventionally loaded and unloaded from transport vehicles by the use of forklifts or cranes. Unfortunately, such systems require that equipment be available at each point at which a container is to be loaded or unloaded from a transport vehicle. This limits the available points of delivery or pickup for goods being shipped or requires that the transporting vehicle be retained in an area where goods are to be loaded or unloaded for often lengthy periods of time. By way of example, if a shipping container is to be loaded with household goods for an individual moving from one area to another, it is conventionally necessary for a truck having a trailer to remain at the point of loading until the shipping container is loaded. During this period of time, the motor vehicle and trailer are not being used for their primary purpose of hauling freight from one location to another, thus increasing the cost of shipping.
To overcome the deficiencies with respect to such conventional shipping techniques, shipping systems have been developed which allow shipping containers to be unloaded from a transport vehicle at a point of delivery or at a point of loading until the container is ready for further shipment. In U.S. Pat. No. 3,817,413, a load-carrying body for a vehicle is disclosed which includes a container which is supported by a frame including longitudinal rails mounted to the vehicle. The container is rollable with respect to the vehicle frame and includes vertically positionable legs which support the container when it is rolled from the frame. Unfortunately, this type of transport system uses specialized containers and requires that the containers be exactly aligned with the vehicle both vertically and horizontally during loading and unloading which, in a practical sense, would rarely be possible.
Another example of a detachable truck bed or body is disclosed in U.S. Pat. No 4,076,299 to Dalton. This patent discloses a truck bed which is elevated from the frame of a truck by the use of hydraulic cylinders. After the bed has been raised a plurality of legs are lowered into engagement with the ground thereby supporting the bed above the truck frame. The truck is thereafter driven from under the truck bed. Unfortunately, with this type of system, the hydraulic cylinders are only provided on the truck frame and thus the support frame cannot be self-loading or unloading on conventional shipping vehicles including railway flat cars or conventional flat bed trucks. In addition, the patent does not provide for a precise alignment between the removable truck bed and the truck frame.
Another type of container transport system is disclosed in U.S. Pat. No. 4,053,073 to Franchin. In this system, the containers which are to be transported by a vehicle include hydraulic cylinder lifts at each corner. In this manner, when it is desired to elevate the container from the vehicle, the cylinders are activated and the container is raised. Unfortunately, with this type of system, the cylinders also function as the support legs for the container. Therefore, extremely large hydraulic cylinders must be provided so as to enable the containers to be lifted to a height of approximately 51" or more. Thereafter, the fluid cylinders must support the weight of the cargo container for extended periods of time. Such a system is highly impractical and expensive.
In U.S. Pat. No. 3,995,760 to Burgdorf et al., a motor vehicle container transport and support system is disclosed wherein containers are supported on frames which are detachably mounted to a cradle mounted to a vehicle bed such as the bed of a tractor trailer. This patent discloses that the cradle provides a means for aligning the support frame with respect to the vehicle during loading and unloading. The patent further discloses the use of an interlock system for securing the containers to the frame. When it is desired to release the frame from a motor vehicle, the legs of the frame are first extended outwardly with respect to the frame and the legs lowered vertically. Once the legs are in contact with the ground the vehicle may be moved with a sliding motion being established between the frame and the cradle. Unfortunately, this type of sliding between the frame and the cradle is not practical and a great deal of stress is imparted to the support legs during loading and unloading. With this system, the frame for supporting the shipping container is locked to the cradle by locking mechanisms similar to that provided for locking a container to the frame. This requires separate activation of a plurality of locking mechanisms to secure the frame to the cradle.
Some additional examples of prior art systems are disclosed in U.S. Pat. Nos. 2,478,578 to Gottshall, 3,119,503 to Herpich et al., 3,152,709 to Fowler, 3,722,948 to Walsh et al., 3,724,697 to Arvidsson, 4,000,924 to Blasingame, 4,089,539 to Berger, and 4,339,148 to Smith et al.